Improvement in sliding square and caliper



LYSANDER L. LAMisg'or EITGHBURG, MASSAoliUsfrrs.Lv

Letters Patent No. 99,917, dated February 15, 1870.

IMPROVEMENT IN SLIDING- SQUARE AND CALIPER.

The Schedule referred to in these Letters Patent and making part of the same To all whom it fmay concern Be it known that I, LYSANDER L. LAMB, of Fitchburg, in the county of Worcester, and State of Mas.- sachusetts, have invented a new and useful Improvement in Sliding Square and I do hereby declare that the following is a full and exact description of the same, reference bein g had to the accompanyingr drawings and to the letters of reference marked thereon.

This invention consists in the employment of a spring of' peculiar construction for retaining the movable part of a sliding square in any desired position.

In the drawings- Figure 1 is a side elevation of the square complete;

Figure 2, a sideelevation of the movable part detached; and

Figure 3, au end view ofthe same. l

To enable others skilled in the art to which my invent-ion appertains to make and use the same, I will now proceed to describe fully its construction audgoperation.

A represent-s the square proper, which is constructed in the usual well-known manner.

B represents the movable part consisting of the L- shaped piece l) and socket b', through which latter passes the long arm ot' the square A.

O represents the spring, which consists cfa base, c, and curving arms c', as shown. rlhe outercnds ofthe base ofthe spring bear upon the square, but by press-v ing its lower ends c c together, these parts are lifted from the square, and the movable part is i'ee to slide thereon.

The specific construction shown is exceedingly desirable.

rlhe upper curves of the spring are adapted to be easily held by the hand, anda grasp sutliciently strong to move the slide will be strong enough to li'ee thel 

